The high-profile trial of eight former police officers accused of torturing detainees in Russia's Republic of Tatarstan has begun.

All the defendants pleaded not guilty as the trial opened in Kazan on September 17.

They have been charged with abusing their positions, forging arrest documents, and the deliberate infliction of serious bodily harm. They were arrested last year.

Fourteen people who say they were tortured by the police officers filed lawsuits after a 52-year-old Kazan resident was allegedly raped with a champagne bottle and tortured to death while in custody at a police station in Kazan in March 2012.

The death led to a wave of protests against police brutality across Russia.

Tatar police officials, including the republic's interior minister, resigned in the wake of the scandal.